<?php
/**
 * A version of Config to be extended by file handling config classes.
 */
class Config_File extends Config {
	/**
	 * Constructor.
	 *
	 * @param string $filename
     * @throws Config_Exception
	 */
    public function __construct($filename) {
        parent::__construct();
		if(!file_exists($filename)) {
			throw new Config_Exception("'$filename' does not exist");
		}
    }
}
?>